1 files changed, 57 insertions, 0 deletions

diff --git a/src/math/math.cpp b/src/math/math.cpp
new file mode 100644
index 00000000..b76db4ae
--- /dev/null
+++ b/src/math/math.cpp
@@ -0,0 +1,57 @@
+#include "common.h"
+#include "patcher.h"
+#include "Quaternion.h"
+
+// TODO: move more stuff into here
+
+void
+CQuaternion::Slerp(const CQuaternion &q1, const CQuaternion &q2, float theta, float invSin, float t)
+{
+	if(theta == 0.0f)
+		*this = q2;
+	else{
+		float w1, w2;
+		if(theta > PI/2){
+			theta = PI - theta;
+			w1 = sin((1.0f - t) * theta) * invSin;
+			w2 = -sin(t * theta) * invSin;
+		}else{
+			w1 = sin((1.0f - t) * theta) * invSin;
+			w2 = sin(t * theta) * invSin;
+		}
+		*this = w1*q1 + w2*q2;
+	}
+}
+
+void
+CQuaternion::Get(RwMatrix *matrix)
+{
+	float x2 = x+x;
+	float y2 = y+y;
+	float z2 = z+z;
+
+	float x_2x = x * x2;
+	float x_2y = x * y2;
+	float x_2z = x * z2;
+	float y_2y = y * y2;
+	float y_2z = y * z2;
+	float z_2z = z * z2;
+	float w_2x = w * x2;
+	float w_2y = w * y2;
+	float w_2z = w * z2;
+
+	matrix->right.x = 1.0f - (y_2y + z_2z);
+	matrix->up.x = x_2y - w_2z;
+	matrix->at.x = x_2z + w_2y;
+	matrix->right.y = x_2y + w_2z;
+	matrix->up.y = 1.0f - (x_2x + z_2z);
+	matrix->at.y = y_2z - w_2x;
+	matrix->right.z = x_2z - w_2y;
+	matrix->up.z = y_2z + w_2x;
+	matrix->at.z = 1.0f - (x_2x + y_2y);
+}
+
+STARTPATCHES
+	InjectHook(0x4BA1C0, &CQuaternion::Slerp, PATCH_JUMP);
+	InjectHook(0x4BA0D0, &CQuaternion::Get, PATCH_JUMP);
+ENDPATCHES